There are a series of shortcut keys that may help you use this thesaurus tool more efficiently:

F1 - Find Synonyms
F2 - Find Synonymous Headwords
F3 - Suggest Headwords
F4 - Find Online
F5 - History and Favorites

ESC - Clear search box

Shift + Enter - Launch and look up word in WordWeb

Insert - fill in the search box with the first word/phrase that
appears in the suggestion list when you are entering a query